Inflatable device of predetermined surface contour and method of making same



Nov. 10, 1959 Original Filed Aug. 15, 1955 INFLATABLE DEVICE OFPREDETERMINED SURFACE c. E. NEISLER, JR., ETAL 2,912,033

CONTOUR AND METHOD OF MAKING SAME 5 Sheets-Sheet 1 FIG. 2

44 7 FIG. 5

' INVENTORS Z4- 16 I J Cfiarvl/lzk/bta/i P'au/ jfiufley {ch Ci Q.

ATTORNEYS 1959 c. E. NEISLER, JRHETAL 2,912,033

INFLATABLE DEVICE OF PREDETERMINED SURFACE CONTOUR AND METHOD OF MAKINGSAME Original Filed Aug. 15, 1955 5 Sheets-Sheet 2 FIG. 6 7

22 PIC-3.8

IN V EN TORS Cfiar/es )5. MIG/eff): BY Pav/ Mz/my CkL ATTORNEYS 1959 c.E. NEISLER, JR., ETAL 2,912,033

INFLATABLE DEVICE OF PREDETERMINED SURFACE CONTOUR AND METHOD OF MAKINGSAME Original Filed Aug. 15, 1955 3 Sheets-Sheet 3 FIG. ll

B G Z m M H 11 G i 1 u l a WI 1 F 6 W m M w .a v I w m 9 0 y m y H F 2 22 2 1 M 1 M wmw M 1 on 0 6 8 0 4 00 um ma 0 2 D \W 0 9 M N a w w s: m mT. v E Ne n N WW R mfM m J T k A v u a um A Y B Patented Nov. 10, 1959INFLATABLE DEVICE OF PREDETERMINED SUR- CONTOUR AND METHOD OF MAKINGCharles Eugene Neisler, Jr., and Paul Mauney, Kings Mountain, N.C.,assignors to Neisler Brothers Incorporated, a corporation of NorthCarolina Original application August 15, 1955, Serial No. 528,426, nowPatent No. 2,872,690, dated February 10, 1959. Divided and thisapplication October 13, 1958, Serial No. 766,979

9 Claims. (Cl. 152-9) This invention relates generally to an inflatabledevice of predetermined surface contour and method of making same.

One object of the present invention is the provision of a light weight,internally reinforced, and readily collapsible inflatable device whichmay be of any desired surface contour, said device being utilizable fora multitude of utilitarian applications in any desired form, such as inthe form of floats, pontoon bridges, buoyant life raft sections, vehicletraction devices, air foils or air foil sections, etc. It has also beenproposed to utilize an inflatable device formed pursuant to the presentinvention for the formation of a landing field, or landing fieldsections.

Another object of the present invention is the provision of aninflatable device of predetermined surface contour which is providedwith internally disposed structure for reinforcing the device andpredetermining the shape there of, said internal structure including aseries of tension elements which are oriented in a novel manner forreinforcing associated surface portions of the device.

Another object of the present invention is the provision of aninflatable vehicle traction device which is of light weightconstruction, readily collapsible, and which is capable of supporting aheavy load with low pressure inflation, said traction device beingadapted to be driven from a centrally disposed drive part or hub member.

Another object of the present invention is the provision of aninflatable vehicle traction device of the above character which isprovided with a series of internally disposed tension elements forinternally reinforcing the easing and transmitting the torque appliedthereto from a centrally disposed drive part.

Another object of the present invention is the provision of a vehicletraction device of the above character in which the drive part and thecasing walls associated with said drive part are relatively rotatablewhereby to inhibit the direct transmission of torque from said part tosaid walls.

Yet another object of the present invention is the provision of a methodof making an inflatable device of predetermined surface contour of theaforenoted construction which is simple in character, and which readilylends itself to low cost mass production.

The above and other objects, features and advantages of the presentinvention will be more fully understood from the following descriptionconsidered in connection with the accompanying illustrative drawings.

In the drawings which illustrate the bestmodes now contemplated by usfor carrying out our invention;

Fig. 1 is a perspective view of a length of mattress fabric which isadapted to be formed into an inflatable device of predetermined surfacecontour;

Fig. 2 is a sectional view, on an enlarged scale, taken on the line 22of Fig. l;

, Fig. 3 is a sectional view, on an enlarged scale, taken on the line 33of Fig. 1;

Fig. 4 is a view similar to Fig. 3 showing a series of tie elementsassociated with a companion -series of flexible elements for drawing thelatter inwardly of the mattress fabric a predetermined amount pursuantto the present invention;

Fig. 5 is a diagrammatic vertical sectional view of a semi-finishedinflatable device of predetermined surface.

contour;

ished inflatable device of predetermined surface contour formedaccording to the present invention;

Fig. 7 is a view similar to Fig. 4 illustrating a modified arrangementfor drawing the flexible elements inwardly of the mattress fabric;

Fig. 8 is a view similar to Fig. 6 corresponding to the embodiment ofFig. 7; i v

Fig. 9 is a fragmentary diagrammatic representationof a modified form ofinflatable device of predetermined surface contour;

Fig. 10 is a front perspective view of a vehicletraction device formedaccording to the present invention, shown mounted to a vehicle;

Fig. 11 18 a sectional view, on an enlarged scale, taken on the line 11ll of Fig. 10;

Fig. 12 is a sectional view, on an enlarged scale, taken on the line1212 of Fig. 11;

Fig. 13 is a fragmentary vertical sectional view of a modified form ofvehicle traction device; and

Fig. 14 is a view similar to Fig. 13 showing a further modified form ofvehicle traction device.

Referring to the drawings, and more particularly to Figs.

flexible elements 22 include a series of flexible elements,

22a which are secured at their opposite ends to the opposite sides 14and 16, respectively, of the casing, and a series of flexible elements22b which are secured at their opposite ends to their associatedopposite side wall portions 18 and 20.

In order to orient the flexible elements 22b in radially extendingdispositions, there is provided a series of tie elements 24 which drawthe flexible elements 22b inwardly of the wall portions 18 and 20 andretain said flexible elements in such inwardly drawn dispositions. Eachof the tie elements 24 is looped around a companion series of flexibleelements 22 disposed in a row r as best shown in Fig. 4 and the oppositeends of said internally reinforcing said opposite wall portions. Thusthe tie elements 22!) extend radially from an associated opposite end28, 30 of the tie elements 24 to an associated opposite wall portion 18,20 for internally reinforcing the latter in the inflated condition ofthe casing 12. From the above it will be apparent that the series offlexible elements 22a internally reinforce the walls 14 and 16 whereasthe radially extending flexible elements 1 through 6 thereof, there isshown an inflatable device 10 of predetermined surface contour whichcomprises a casing 12, formed of flexible fluid impervious material,which in its inflated condition defines said pre-".

3 22b internally reinforce the opposite wall portions 18 and 20, saidflexible elements constituting tension elements in the inflatedcondition of the casing 12. In the inflated condition of the casing 12the tie elements 24 extend substantially medially of the opposite sides14 and 16 of the casing in a plane substantially parallel to I saidopposite sides, it being noted that the tie elements 24 are loopedaround the elements 22 without any direct securement thereto so that theinflation of the casing will be effective to position said tie elementsin such medial plane. The tie elements 24 of the embodiment of Figs. 1through 6 are constituted by lengths of cord which are looped aroundcompanion groups of flexible elements 22, although it will be apparentthat said tie elements may be constituted by other than cords and thatthe series of flexible elements 22b may be retained in the desiredinwardly drawn dispositions in any desired manner. Any number offlexible elements 22b may be drawn inwardly of the opposite wallportions 18 and 20 and may be so drawn to any desired degree whereby topredetermine the contour of said opposite wall portions. In theillustrated embodiment of Figs. 1 through 6, the opposite Wall portions18 and 20 are of generally arcuate configuration with the flexibleelements 22b shown radially extending a uniform amount from the oppositeends 28 and 30 of the tie cords 24, it being apparent that the tie cordsand the series of flexible elements 22b may be relatively arranged inany predetermined manner in accordance with the desired contour and thedesired internal reinforcement of the opposite wall portions 18 and 20.While the tie cords 24 are shown as being looped around companion rows rof flexible elements 22, it will be apparent that, if desired, said tiecords may be directly secured to such flexible elements or to selectedflexible elements in any desired manner whereby to retain said rows inthe desired drawn dispositions. The inflatable device is formed from ablank or length of mattress fabric 32 pursuant to the method now to bedescribed in detail.

The mattress fabric 32 may be of any conventional construction or may beof the construction disclosed in application Serial No. 360,435, filedJanuary 9, 1953, now Patent No. 2,848,018 for Improvements in Fabric andMethod of Making Same in the name of Charles" E. Neisler, Jr. andassigned to the assignee herein. The mattress fabric 32 of theillustrated embodiment comprises a pair of woven fabrics 34 and 36having intermediate threads 38 extending therebetween and woven thereto,said pair of fabrics being disposed in laterally spaced confrontingdisposition with the intermediate threads 38 being transversely disposedbetween the fabrics 34 and 36. If a greater spacing between the fabrics34 and 36 is desired than is obtainable by the use of conventionalmethods and apparatus, mattress fabric formed pursuant to the disclosureof the above referred to copending application may be utilized. It willalso be understood that the fabrics 34 and 36 may be of any conventionalconstruction and may be formed of any suitable material and similarlythe threads 38 may be formed of any suitable material and may beintegrated with the fabrics 34 and 36 in any desired manner.Accordingly, while the mattress fabric 32 is woven on a conventionalloom it will be understood that it is within the scope ofthe presentinvention to form such fabric in any desired manner whereby to provide apair of spaced fabrics interconnected by transversely extending threads,or the like.

The threads 38 are adapted to form the flexible elements 22 of theinflatable device 10 and are accordingly adapted to internally reinforcesa d device. The opposite sides 40 and 42 of the fabric 32 are adaptedto be internally reinforced by the flexible elements 22b and to this endthe rows r of threads 38, which extend between the sides 40 and 42, aredrawn inwardly of the fabric 32 by the tie elements 24 in the mannerdescribed above. Thus a tie cord 24 is looped around each row r ofthreads 38 extending between the opposite sides 40 and 42 of the fabric32 and the free ends of the tie cords are tied as indicated at 26 in amanner to retain the threads 38b of the rows in inwardly drawndispositions relative to the opposite sides 40 and 42. Thus a series ofthreads or flexible elements 38b, adjacent the opposite ends of the tiecords 24, will be drawn and retained inwardly of the opposite sides 40and 42 of the fabric 32 and said flexible elements are adapted to definethe flexible elements 22b which internally reinforce the opposite wallportions 18 and 28 of the inflatable device 10. The threads or flexibleelements 38a disposed between the flexible elements 3812, are adapted todefine the flexible elements 22a of the inflatable device 10 and areaccordingly adapted to internally reinforce the opposite side walls 14and 16 of said inflatable device. Thus the rows r of threads or flexibleelements 33 may be uniformly or non-uniformly drawn inwardly of thefabric 32 to any desired degree and may be retained in inwardly drawndispositions by means of the tie cords 24. The series of tie cords 24extend transversely of the flexible elements or threads 38 and arelaterally spaced corresponding to the spacing of the rows r of threadsor flexible elements 38. The fabrics 34 and 36 are now in condition tobe manipulated to define the casing 12, shown in Fig. 5, which is in asemi-finished condition.

The free longitudinally extending marginal edges 44 and 46 at theopposite wall portions 18 and 20 of casing 12' are secured together inoverlapping disposition in any suitable manner, for example by a sewingoperation, an adhesive securing operation, or the combination thereof.The casing 12 is provided with an external layer 48, as shown in Fig. 6,of any fluid impervious material such as rubber, rubber compounds,plastic or the like to render the casing 12 of the finished inflatabledevice 10 fluid impervious and to impart to said casing the requisiteexternal surface characteristics for the particular application of theinflatable device. It will be apparent that the external layer 48 may beapplied to the external surfaces of the casing 12 in any desired manner.A suitable conventional valve 50, which provides for the controlledinflation and deflation of the casing 12, is suitably integrated with awall portion of the casing. From the above it will be apparent that thesemi-finished inflatable device 10' is formed into a finished inflatabledevice 10 by securing the marginal edges 44 and 46 to each other asdescribed above and applying to the casing 12 an external layer 48 torender the casing fluid impervious. Thus the flexible elements 22internally reinforce the inflatable device 10 and provide for thedesired distribution of stresses applied to the casing 12. Each of theflexible elements 22 transmits and distributes the stresses applied tothe inflatable device to an adjacent area of the casing whereby theprovision of the series of elements 22 will effect a substantialreinforcement of the casing. The flexible elements 22 may be arrangedand spaced in any desired manner in the casing and said elements arepreferably disposed in closely adjacent rela tion in order to provide auniform distribution and transmission of the casing stresses. Ifdesired, the tie cords 24 or similar devices may be utilized tointernally reinforce an opposite pair of wall portions, corresponding tothe ends 52 and 54 of the fabric 32, in which case the tie cords 24 willbe associated with companion rows of threads or flexible elements 38extending between said fied arrangement for drawing the flexibleelements 38 inwardly of the opposite wall portions 40' and 42 and forretaining said flexible elements in such inwardly drawn dispositions.The embodiment of Figs. 7 and 8 is similar to'the first describedembodiment except that a pair of laterally spaced relatively rigid tiemembers 60 and 62 are utilized in place of the tie cords 24 of the firstdescribed embodiment for a similar purpose. The tie members 60 and 62may have any desired degree of rigidity and are retained inpredetermined spaced relation by means of a series of connectingelements 64, which may be constituted by lengths of wire, flexiblecords, or the like. If desired, the connecting elements 64 may berelatively rigid so as to define with the tie members 60 and 62 arelatively rigid frame for applications in which such a relatively rigidframe is desired. The connecting elements 64 may be headed at theiropposite ends as indicated at 66 in any suitable manner in order toprovide for the retention of the tie members 60 and 62 in predeterminedspaced relation. From the above it will be apparent that the tie members60 and 62 will be effective to retain the series of flexible elements22b in inwardly drawn dispositions in the manner described above wherebyto internally reinforce associated wall portions in the manner describedabove in detail, it being noted that the flexible elements 22acorrespond to the flexible element 22a of the first describedembodiment. Thus the flexible elements 22 may be retained in the abovedescribed dispositions by means of the series of tie cords 24 or bymeans of the relatively rigid tie members 68 and 62 which are suitablyretained in predetermined spaced relation.

With reference to Fig. 9, there is shown a section 70 of an inflatabledevice of airfoil surface contour, said surface contour beingpredetermined in the manner described above by the inward drawing of therows r of flexible elements 72, which correspond to the elements 38 ofthe first embodiment. The rows r of flexible elements 72 are drawninwardly of the Walls 74 and 76 a progressively greater amount towardsthe end 78 of the section '70, corresponding to the desired surfacecontour, said section being formed pursuant to the method describedabove in detail except that the rows 1'' of flexible elements 82 arenon-uniformly drawn and retained in wardly of the opposite walls 74 and76. Thus the tie cords 24', which are utilized to inwardly draw theflexible elements 72 and to retain the latter in their inwardly drawncondition, are of progressively shorter length towards the end 78 of thesection 70 whereby it will be apparent that an inflatable device ofinternally reinforced construction may be formed having any desiredcontour utilizing the method described above in detail.

With reference to Figs. -12, there is shown a traction device 80 whichis formed pursuant to the present invention and which is of the generalcharacter of the traction device disclosed in our application, SerialNo. 504,435, filed April 28, 1955, now Patent No. 2,824,592, for VehicleTraction Device and Method of Making Same, said application beingassigned to the assignee herein. In Fig. 10 the traction device 80 isshown mounted across the front end of a vehicle V for supporting saidvehicle for movement over the ground, said traction device comprising acasing 82 formed of flexible fluid impervious material which is adaptedto be inflated to a relatively low pressure, although it will beunderstood that said casing may be inflated to a relatively highpressure, if desired. The casing 82 is formed of fabric materialcorresponding to fabric material 32 having relatively long flexibleelements 38 extending between the laterally spaced fabrics 34 and 36, itbeing understood that such fabric material may be formed in the mannerof the above referred to copending application. The casing 82 comprisesa cylindrical wall 84 which forms the rolling surface of the tractiondevice and oppositely disposed end walls 86 and 88, there being provideda axis of revolution of the traction device, it being understood thatsaid tie members generally correspond to the tie members 60 and 62 ofthe embodiment of Figs. 7 and 8. Thus the opposite ends of the flexibleelements 90 are secured in spaced relation to the cylindrical wall 84and are looped around a companion rigid tie member 92. The cylindricalshape of the wall 84 is imparted thereto by drawing the tie members 92towards each other the requisite amount to impart to such a wall asubstantially circular cross section, said members 92 being in closelyadjacent relation. From the above it will be apparent that by drawingthe flexible elements 90, which correspond to the elements 22 of thefirst embodiment, uniformly inwardly a sufficient amount as by meansofthe tie members 92 an inflatable device of generally circular crosssection may be obtained. The tie members 92 are retained in the desiredpredetermined relation and are rigidly coupled to each other by means ofa pair of coupling devices 94 which are associated with the opposite endwalls 86 and 88 of the casing. The opposite ends of the tie members 92are secured tothe coupling parts 96 of the coupling devices 94 in anysuitable manner, for example by means of a headed portion 98 provided onthe opposite ends of the tie members, said headed portions beingdisposed in complementary recesses 100 provided in said coupling parts96. It will be noted that the coupling part 96, shown in Fig. 12, isapertured therethrough as indicated at 102 for the extensiontherethrough of one end of the tie bars 92. While there is illustratedin Fig. 12 a single coupling device 94 which is associated with the endwall 88 it will be understood that the opposite end of the casing 82 issimilarly constituted and is provided with a coupling device 94associated with the end wall 86. The inner portions 104 and 106 of theend wall 88 are disposed in overlapping disposition and are secured influid sealing relation by means of the coupling device 94. Moreparticularly, the portions 104 and 106 are clamped between the couplingpart 96 and the complementary coupling part 108 by means of the seriesof peripherally spaced clamping bolts 110. The coupling part 108 isprovided with a projecting shaft portion 112 which constitutes the driveshaft for the vehicle traction device, said drive shaft or part beingadapted to be driven from any suitable power source through theintermediation of the chain drive. 114 shown in Fig. 10. Thus thecoupling devices 94 effectively couple the tie members 92 to each otherand to the drive shaft 112 and also provide for an effective seal at theend walls 86 and 88. The torque applied by the drive shaft 112 will betransmitted to the casing by means of the series of flexible elements 90in the manner described in detail in the aforereferred to copendingapplication, Serial No. 504,435, now Patent No. 2,824,592. The members92 and coupling devices 94 define the axis of revolution of the vehicletraction device and are driven from the drive shaft 112 for driving thetraction device, it being understood that the elements 90, which are ofsubstantially uniform length, are effective to transmit the torque fromthe drive shaft 112 and its associated tie members 92 to the wall 84 ofthe casing 82. Thus the vehicle traction device 80 is generally similarto the vehicle traction device of our above referred to copendingapplication, Serial No. 504,435, now Patent No.

2,824,592, except that the vehicle traction device 80 is formed pursuantto the present invention in which the tie members 92 are drawn inwardlytowards each other for correspondingly orienting the flexible elements90, as described above. Accordingly, a casing or inflatable device ofany predetermined configuration may be formed pursuant to the presentinvention, it being apparent that the specific configurationsillustrated and described herein are given by way of example only. Theend Wall 88 is provided with a conventional valve 116 for inflating anddeflating the air chamber defined by the casing '82 and the latter hasan external layer 118 of fluid impervious material such as rubber,rubber compounds or the like to render said casing fluid impervious andto impart to the latter a frictional running surface. The casing 82 andthe flexible elements 90 disposed therein may be formed of any suitablematerial and said elements 90 may be spaced in the casing in any desiredmanner.

In order to inhibit the direct transmission of torque from the driveshaft 112 to the end walls 86 and 88 there is provided an arrangementshown in Fig. 13 in which the end walls 86 and 88' are rotatably mountedrelative to the drive shaft 112' and the structure coupled thereto. Inthe arrangement shown in Fig. 13 the coupling part 96' is secured to thedrive shaft 112 by means of a transverse pin or key 129. Thus therotation of the shaft 112 will be effective to rotate the coupling part96' and the tie members 92' coupled thereto so as to transmit the torquefrom the drive shaft to the cylindrical wall 84 of the casing. The shaft112 extends through the casing 82 and through the coupling part 96'which is apertured as indicated at 122 for the extension therethrough ofsaid drive shaft. The shaft 112' is rotatably mounted relative to thecoupling device 124, the latter comprising a pair of complementarymembers 126 and 128 between which the inner portions 104' and 106' ofthe end wall 88' are clamped in fluid sealing relation. The members 126and 128 are retained in clamped engagement by means of the series ofperipherally spaced bolts 130. Thus the drive shaft 112 is rotatablerelative to the clamping device 124 and the end wall 88' clamped theretowhereby the rotation of said drive shaft will not directly transmit thetorque thereof to the end wall 88. The clamping device 124 is retainedin position on the shaft 112 by means of a suitable snap ring 132disposed in the peripheral groove 133 of said shaft. The clamping member128 is recessed as indicated at 134 and disposed in said recess are apair of sealing rings 136 which provide a fluid seal at the shaft 112.It will be apparent from the above that if slack is provided in theflexible elements 90' or if the latter should elongate in normal usageno adverse effect will be realized in this arrangement as the torque ofthe drive shaft will not be applied directly to the end walls on therotation of the drive shaft since the latter is rotatably mountedrelative to said end walls. Thus where slack is provided or develops inthe flexible elements 96', the rotation of the shaft 112 will beeffective to take up such slack at which time the torque of the driveshaft will be transmitted to the casing 82' by means of said flexibleelements. Thus the provision of the relative rotation between the driveshaft and the end walls inhibits the direct transmission of substantialtorque from said drive shaft to the end Walls whereby to minimize oreliminate the danger of rupturing or weakening such end walls.

With reference to Fig. 14, there is shown a vehicle traction devicewhich is similar in all respects to the embodiment of Fig. 13 exceptthat the casing structure 82" apart from the clamping devices is formedpursuant to the disclosure of our above referred to copendingapplication, Serial No. 504,435, now Patent No. 2,824,592. The clampingdevice 124" corresponds in all respects to the clamping device 124described above with the torque transmission elements being constitutedby a series of sheet material portions or segments 140 which are adaptedto transmit the torque of the drive shaft 112 to the casing. The rods142 are supported at their opposite ends by means of retainer members144, each rod being extended through a looped end 145 of the segments140 and a companion pair of aligned apertures 146 provided in saidretainer members. Thus the torque transmission elements .140 and thesecurement of such elements relative to the shaft 112" correspond in allrespects to the arrangement illustrated and described in theaforereferred to copending application, Serial No. 504,435, now PatentNo. 2,824,592. Accordingly, the shaft 112" is rotatable relative to theend wall 88" and the opposite end wall (not shown) so as to inhibit thedirect transmission of substantial torque from said drive shaft to saidend walls whereby to prevent excessive stresses being applied to saidend Walls especially where the torque transmission elements 146 haveslack. Thus the embodiment of Fig. 14 corresponds in all respects to theembodiments disclosed in our copending application, Serial No. 504,435,now Patent No. 2,824,592, with the addition of clamping devices 124"which provide for the rotation of shaft 112" relative to its associatedcasing end walls. While in the embodiments of Figs. 12, 13 and 14 onlyone casing end wall and an associated clamping device is shown, it willbe understood that the opposite casing end wall will be similarlyconstituted and will be provided with a similar clamping device.

Certain features of the present invention are disclosed in ourapplication, Serial No. 504,436, filed April 28, 1955, for InflatableDevice of Predetermined Surface Contour and Method of Making Same, saidapplication being assigned to the assignee herein, now Patent No.2,824,589.

This application is a division of our application, Serial No. 528,426,filed August 15, 1955, now Patent No. 2,872,690.

While we have shown and described the preferred embodiments of ourinvention, it will be understood that various changes may be made in theidea or principles of the invention within the scope of the appendedclaims.

Having thus described our invention, what we claim and desire to secureby Letters Patent is:

l. A vehicle traction device, comprising a fluid-impervious inflatableflexible casing having a pair of laterally spaced relatively rigid tiemembers collectively forming the axis of revolution of the tractiondevice secured thereby, means for coupling said tie members in saidspaced relation, said casing comprising a cylindrical wall forming therolling surface of the traction device and end Walls, said couplingmeans including a part extending through one of said end walls fordriving the device, and a radially extending series of flexible elementsdisposed internally of said casing and connected to said cylindricalwall and extending around a companion tie member for transmitting thetorque of said tie members to said cylindrical wall, and means providingfor the relative rotation of said coupling means and said end walls.

2. A vehicle traction device, comprising a fluid-impervious inflatableflexible casing including oppositely disposed end walls, having rigidstructure secured therein defining the axis of revolution of thetraction device, means extending between said structure and said casingfor transmitting the torque applied to said structure to said casing,and means providing for the relative rotation of said structure and saidend walls.

3. A vehicle traction device, comprising a fluid-impervious inflatableflexible casing having rigid structure secured thereby defining the axisof revolution of the traction device, said casing comprising acylindrical wall forming the rolling surface of the traction device andend Walls, said structure extending between said end walls in a fixedrelative disposition and having a part extending through one of said endwalls in fluid sealing relation therewith for driving the device, aradially extending series of flexible elements extending between saidstructure and said cylindrical Wall for transmitting the torque appliedto said structure to said cylindrical wall, and means providing for therelative rotation of said structure and said end Walls whereby toinhibit the direct transmission of torque from said part to said endwalls.

4. A vehicle traction device, comprising an inflatable casing formed offlexible fluid-impervious textile material comprising a cylindrical Wallforming the rolling surface of the traction device and end walls, saidhub member extending through said end walls in fluid sealing relationtherewith and being rotatably mounted relative to said end walls, aradially extending series of flexible elements disposed internally ofsaid casing and connected tosaid cylindrical wall and said hub member,respectively, for transmitting the torque of said member to saidcylindrical Wall, and means providing for the relative rotation of saidhub member and said end Walls whereby to inhibit the direct transmissionof torque from said hub member to said end walls.

5. A method of making a vehicle traction device of the characterdescribed, comprising the steps of providing fabric material formed of apair of fabrics having a series of flexible elements extendingtherebetween and secured thereto, drawing said flexible elementsinwardly of said fabric material and retaining said elements in saiddrawn condition to thereby orient said elements in predetermineddispositions, and forming an inflatable casing from said fabric materialwhereby in the inflated condition of said casing said elements will beoriented in predetermined radially extending dispositions to definetorque transmission elements for said casing.

6. A vehicle traction device, comprising a fluid impervious inflatableflexible casing having an outer peripheral wall and being provided withtorque transmission means disposed internally thereof, said torquetransmission means comprising a series of flexible elements extendinginternally into said casing from said outer peripheral wall thereof andsecured at their opposite ends to opposite outer peripheral wallportions, respectively, of said casing, and means extending transverselyof said flexible elements for orienting at least several of the latterin a predetermined disposition and for retaining said several elementsin said disposition in the inflated condition of said casing, said meansdefining the axis of revolution of said traction device.

7. A vehicle traction device, comprising a fluid impervious inflatableflexible casing having an outer peripheral wall and being provided withtorque transmission means disposed internally thereof, said torquetransmission means comprising a series of flexible elements extendinginternally into said casing from said outer peripheral wall thereof andsecured at their opposite it) ends to opposite outer peripheral wallportions, respectively, of said casing, and a pair of laterally spacedrelatively rigid tie members extending transversely of said flexibleelements and secured in a predetermined spaced relation for drawing saidflexible elements inwardly towards the axis of revolution of said casingto thereby orient said elements in a predetermined disposition wherebyto define tension elements for transmitting the torque applied to saidtie members to said casing.

8. A vehicle traction device, comprising a fluid impervious inflatableflexible casing having an outer peripheral wall and being provided withtorque transmission means disposed internally thereof, said torquetransmission means comprising a series of flexible elements extendinginternally into said casing from said outer peripheral wall thereof andsecured at their opposite" ends to opposite outer peripheral wallportions, respectively, of said casing, a pair of laterally spacedrelatively rigid tie members extending transversely of said flexibleelements and secured in a predetermined spaced relation for drawing saidflexible elements inwardly towards the axis of revolution of said casingto thereby orient said elements in a predetermined disposition wherebyto define tension elements for transmitting the torque applied to saidtie members to said casing, and means for coupling said tie members insaid predetermined relation, said coupling means defining said axis ofrevolution and being adapted to be driven to drive the traction device.

9. A vehicle traction device, comprising a fluid ime pervious inflatableflexible casing including an outer peripheral wall and oppositelydisposed end walls, said casing having rigid structure secured thereindefining the axis of revolution of the traction device, means extendingbetween said structure and said casing for transmitting the torque tosaid structure to said casing, and means providing for the relativerotation of said structure and said end walls, said torque transmittingmeans comprising a series of flexible elements extending internally intosaid casing and secured at their opposite ends to opposite wallportions, respectively, of said peripheral wall.

References Cited in the file of this patent UNITED STATES PATENTS2,431,897 Wensley Dec. 2, 1947 2,709,982 Staassler June 7, 19552,824,592 Neisler et al. Feb. 25, 1958

